Abstract

In the original version of the Internationalized Domain Names in
Applications (IDNA) protocol, any Unicode code points taken from user
input were mapped into a set of Unicode code points that "made
sense", and then encoded and passed to the domain name system (DNS).
The IDNA2008 protocol (described in RFCs 5890, 5891, 5892, and 5893)
presumes that the input to the protocol comes from a set of
"permitted" code points, which it then encodes and passes to the DNS,
but does not specify what to do with the result of user input. This
document describes the actions that can be taken by an implementation
between receiving user input and passing permitted code points to the
new IDNA protocol. This document is not an Internet Standards Track
specification; it is published for informational purposes.